This invention relates in general to integrated circuits and in particular to an electrically conductive interconnect system for integrated circuits.
With the continual reduction in size of integrated circuits, each component within each circuit is likewise reduced in size. Not only are components such as transistors reduced in size, but also electrically conductive interconnect lines used in integrated circuits, as well as the spacing between these interconnect lines. Such line and spacing definitions can have submicron dimensions.
One equipment commonly used in integrated circuit manufacturing and related to line and spacing definition is a photostepper. A photostepper is used to expose a layer of resist disposed over a semiconductor wafer to electromagnetic radiation spatially modulated with a circuit pattern. The photostepper projects an image of the circuit pattern towards the wafer by means of a reticle or mask. The lower limit of the width of interconnect lines and the spacing between these lines are set by the resolution of the photostepper. Even when the most up-to-date photostepper equipment is used, it is still not possible to manufacture ultra narrow interconnect lines of line width or spacing width of the order of 0.1 micron.
It is therefore desirable to provide a system that can be used to manufacture integrated circuits with interconnect lines of the order of 0.1 micron or less.